The present invention relates to the field of communications systems, and more particularly to a system and method for facilitating hybrid ATM/TDM transport over a common fiber ring.
Communication networks employing fiber optic rings as transmission media are typically limited to transmitting time division multiplexed information, making no provision for the transmission of asynchronous transfer technologies, such as asynchronous transfer mode (xe2x80x9cATMxe2x80x9d) cells. Those systems that do attempt to communicate ATM traffic over a fiber ring typically map ATM cells into synchronous transport mode (STM) signals, and provide no ATM layer processing at nodes residing on the ring. These systems only provide switching of the STM signals carrying the ATM cells, not of the cells themselves.
In accordance with the present invention, a method of transporting ATM cells and TDM information over a common fiber ring comprises receiving a plurality of incoming signals comprising ATM cells, legacy data, or TDM information, formatting the plurality of incoming signals into a first plurality of incoming transport signals comprising ATM cells and a second plurality of incoming transport signals comprising TDM information constructing from the first plurality of incoming transport signals a first outgoing STM signal comprising at least one ATM cell, constructing from the second plurality of incoming transport signals a second outgoing STM signal comprising TDM information and transmitting the first and second outgoing STM signals over a common fiber ring.
Technical advantages of the present invention include a system and method for efficiently communicating signals carrying asynchronous transfer mode cells and signals carrying TDM information over a common fiber ring. Through a variety of configurations and modes of operation, the invention provides flexibility in the distribution of bandwidth between ATM and TDM traffic. In facilitating various bandwidth allocations between TDM and ATM traffic, the invention provides significant advantages in terms of network flexibility and adaptability to future processing demands. In addition, by providing ATM layer processing functionality at at least some of the nodes residing on the fiber ring, the invention facilitates a high granularity in switching ATM information carried in STM signals.
Other technical advantages are readily apparent to one of skill in the art from the attached figures, description, and claims.